Conventionally, Patent Document 1 discloses an ejector that draws a refrigerant through a refrigerant suction port by a drawing effect of a jetted refrigerant jetted at high velocity, the jetted refrigerant and the drawn refrigerant being mixed, a pressure of the mixed refrigerant being increased in the ejector. Patent Document 1 discloses an ejector-type refrigeration cycle that is a vapor-compression-type refrigeration cycle device including the ejector.
In the ejector of Patent Document 1, a passage forming member having a circular cone shape is provided in a body, and a refrigerant passage is defined between the body and a circular cone-shaped side surface of the passage forming member. A cross-sectional shape of the refrigerant passage is a circular annular shape. The most upstream part of the refrigerant passage is used as a nozzle passage through which a high-pressure refrigerant is decompressed and ejected, and the most downstream part of the refrigerant passage is used as a diffuser passage in which the jetted refrigerant and the drawn refrigerant are mixed, a pressure of the mixed refrigerant being increased in the diffuser passage.
Moreover a swirl space, which is a swirl flow generation portion generating a swirl flow in the refrigerant flowing into the nozzle passage, is defined in the body of the ejector of Patent Document 1. In the swirl space, the refrigerant on a swirl center side is decompressed and boiled by being swirled the subcooled liquid-phase refrigerant about a central axis of the nozzle, and a gas-phase refrigerant (air column) having a column shape is generated on the swirl center side. The two-phase separated refrigerant on the swirl center side flows into the nozzle passage.
According to this, in the ejector of Patent Document 1, boiling in the nozzle passage is enhanced, and an efficiency of energy conversion when converting a pressure energy to a kinetic energy in the nozzle passage is intended to be improved.